In production plants such as a semiconductor production plant and an LCD panel production plant, a carrier having an article (for instance, in case of the semiconductor production plant, objects such as a semiconductor substrate, an LCD glass substrate, a photomask glass substrate, and an optical disk substrate) received therein is carried by a carrying system using a carrying conveyor, an OHT, an OHS, and the like in accordance with the processes. In the production plants using the carrying system, in many cases, a plurality of floors are provided with production processes due to an increase in the number of production units and a size of a carrying system in accordance with an increase in a production scale and a size of the production plant. In such a case, a carrying operation is performed between the floors in a vertical direction and on the same floor in a horizontal direction.
Here, in the carrying system in which a load is carried between the floors in terms of a conveyor carrying type, as a known technique for performing the carrying operation in the vertical direction, for instance, Patent Documents 1 and 2 disclose a vertical carrying apparatus such as a lifter having a conveyor function. Patent Document 1 discloses a lifter having a conveyor function, and the lifter conveyor is installed at a load delivering position adjacent to a horizontal portion of a solid loop carrying apparatus provided on the first floor and the second floor so as to perform a roller carrying operation while elevating between the first floor and the second floor. In addition, Patent Document 2 discloses a loading and unloading chain conveyor with a lifter having a function similar to that of Patent Document 1.
In addition, in a carrying system in which a load is carried between floors in terms of a carrying type other than the conveyor carrying type, as a known technique for performing the carrying operation in the vertical direction, there are known a vertical carrying apparatus such as a pantograph-type elevation apparatus and an elevator mounted with a stacker crane and a transfer unit.    Patent Document 1: Japanese Patent Publication No. 6-239416A    Patent Document 2: Japanese Patent Publication No. 5-262407A